I have a 2010 3.5L Sebring Convertible with 103k miles on it. I was driving around town a couple of weeks ago and noticed it was starting to miss. The CEL light eventually came on. Got it home, hooked up code reader, and it was showing a cylinder 4 misfire. I swapped coil pack and plugs with another cylinder to see if the misfire followed, but I still got cylinder 4 misfire. I checked compression and got 90psi on cylinder 4 while all others were 135-140psi. Engine also has a slight ticking noise. I got some combustion chamber cleaner from Chrysler dealer but this only made a slight difference and did not fix anything.

I called a local shop and spoke to a mechanic who has previously worked on another 3.5L. I told him all I had done and was asking if he could do a cylinder leak down test. He said it is probably a valve problem, but he is not interested in pulling the heads to check (or do the cylinder leak down test). The only option he would entertain is replacing the engine.

I checked with my local Chrysler service department and told them what I had done. I was told all they would do is check compression and if it is low, they would recommend replacing the engine. They also said the cylinder leak down would not tell me anything.

I just want someone that will diagnose to tell me what it is. My intent is to try to get it fixed without spending a small fortune so I can trade it in. Is there some reason no one will entertain further diagnosing and repairing? Any suggestions/recommendations?

 

You need to find better technicians! Leak down test will narrow the issue to valves or cylinder wall/ring issue. I personally suspect a worn cam. Tapping and some history with these engines leads there. Valves not opening fully due to a worn cam will affect compress

 

Dealerships are great for "remove and replace". Not so great for "repair" of a component. The mechanic you talked to apparently doesn't have confidence in his own skills and you shouldn't either. Keep looking.

 

Yourmechanic.com

 

maybe faulty injector

 

a fuel injector will not cause low compression.